Device for sealingly closing a metal pressure vessel

ABSTRACT

A pressure chamber in a vessel is closed by a cover which is recessed in the vessel in abutment with a shoulder thereof and retained therein by a detachable support assembly. A semitoroidal sealing member is received in an annular chamber formed by the cover, the support assembly and the inner wall of the vessel and the sealing member opens outwardly and one circumferential edge of the sealing member is welded to the cover and the other circumferential edge is welded to the inner wall of the vessel. The support assembly is constituted by a subdivided annular member partially received in a circumferential recess in the wall of the vessel and an annular inner locking member within the subdivided member and detachably secured to the cover.

United States Patent Schoonman et al.

[541 DEVICE FOR SEALINGLY CLOSING A METAL PRESSURE VESSEL [72] Inventors: Willem Schoonman, Voorschoten; Djin Klan Oey, Rijswijk, both of Netherlands [73] Assignee: Lummus Nederland, N.V., The

Hague, Netherlands [22] Filed: Oct. 7, 1970 [21] Appl. No.: 78,667

[ Foreign Application Priority Data Apr. 7, 1970 Netherlands ..7004982 [52] US. Cl..... ..220/46 MS, 220/55 AN [51] Int. Cl. ..B65d 53/00 [58] Field of Search ..220/46 R, 46 MS, 55 AN, 55 R [56] I References Cited UNITED STATES PATENTS 2,818,993 1/1958 Alt ..220/46 MS 2,298,51 1 10/1942 Rathbun ..220/46 MS 3,161,317 12/1964 .lohanson ..220/46 MS 2,196,895 4/1940 Bowman ..220/46 R 1 51 Sept. 12, 1972 2,690,276 9/1954 Alt ..220/55X Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Edwin D. Grant Attorney-Waters, Roditi, Schwartz & Nissen [57] ABSTRACT constituted by a subdivided annular member partially received in a circumferential recess in the wall of the vessel and an annular inner locking member within the subdivided member and detachably secured to the cover.

6 Claims, 4 Drawing Figures DEVICE FOR SEALINGLY CLOSING A METAL PRESSURE VESSEL BRIEF SUMMARY OF THE INVENTION The invention relates to a device for sealingly closing a metal pressure vessel, and particularly an end chamber of a heat exchanger, by means of a metal cover.

In heat exchangers of known construction, the cover is connected to an end flange of the shell by means of bolts, and a packing ring is enclosed between the cover and the end flange.

However, in view of the very high pressures currently applied in present heat exchangers, i.e., of the order of hundreds of atmospheres, it is no longer possible to obtain a reliable and durable seal in this manner.

It is an object of thepresent invention to provide a device which constitutes an improved sealed closure for a metal pressure vessel, such as an end chamber or channel of a heat exchanger.

For this purpose, the device according to the invention is characterized in that the cover is countersunk in the pressure vessel and rests on its side remote from the pressure space against a support means, which is subdivided around its periphery into a plurality of support elements, which protrude into a circumferential internal recess in the wall of the pressure vessel; the support elements are locked in the recess by a detachable locking means, while a circumferential metal sealing member is welded to the pressure vessel, as well as to the cover on the side thereof facing the support means.

Thus, according to the invention, a metal sealing member is employed, which is connected by means of welding to the pressure vessel as well as to the cover. In this manner an improved and durable seal is obtained, which will resist extremely high pressures. Further, the cover may be easily dismounted. For this purpose the locking means and the support means are removed, whereafter the sealing member is cut through by means of grinding or burning. Thus the accessibility of the pressure vessel, such as an end chamber or channel of a heat exchanger, is fully retained.

If the pressure vessel is cylindrical, the support means consists of a subdivided support ring, while the locking means consists of a locking ring, which fits within said support ring and is connected to said cover by means of bolts.

Further, the outer wall of the cover may be provided with a recessed circumferential portion, which, together with the pressure vessel and the support means, defines an annular chamber and the metal sealing member consists of a hollow semi-toroidal ring which opens toward the wall of the pressure vessel and is received in said chamber.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic front view, partially in section, of an embodiment of a heat exchanger, wherein the channels are sealingly closed by means of a device according to the invention,

FIG. 2 is a section taken along the line IIII in FIG. 1 on a larger scale,

FIG. 3 is a plan view of a support ring composed of a plurality of support elements, and

FIG. 4 is a plan view of a locking ring.

DETAILED DESCRIPTION FIG. 1 schematically shows a heat exchanger comprising a cylindrical metal shell 1 and two tube plates 2. Between these two tube plates 2 there extend a plurality of tubes 3 which open at either end into an end chamber or channel 4. Inlets and outlets 5 are provided for counterflow of fluids, and a heat exchange takes place between the fluids in their passage between their respective inlets and outlets. The directions of flow of these fluids are schematically indicated in FIG. 1 by means of arrows.

Each channel 4 isclosed by means of a metal cover 6, which is recessed or countersunk in the channel 4 and which is retained in the vessel at its side remote from the pressure space by a support ring 7. The ring 7 is subdivided around its circumference into support elements 7 as seen in FIG. 3. The support ring 7 is partly received in an annularinternal recess 8 in the wall of the shell 1 and is locked in the recess 8 by means of a locking ring 9. The locking ring 9 has a plurality of axial bores 10 therein and threaded studs 11 extend through the bores 10 and are screwed into the cover 6 and are locked thereto by means of nuts 11.

An annular metal sealing member 12, consisting of a hollow semi-toroidal ring, which opens toward the shell 1, is welded to the shell 1, as well as to the side of the cover 6 facing the support ring 7.

As particularly shown in FIG. 2, the outer wall 13 of the cover 6 remote from the pressure channel 4 is provided with a recessed circumferential portion 14, which, together with the shell 1 and the support ring 7, defines an annular chamber for receiving the sealing member 12.

The outer wall 13 of the cover 6 is further provided with an annular shoulder 15, which adjoins the recessed circumferential portion 14 and which surrounds an outwardly protruding central portion 16 of the cover 6. The locking ring 9 fits around this central portion 16 and rests, together with a foot 17 of the support ring 7, against the shoulder 15.

When the cover 6 is to be mounted in place, the semi-toroidal sealing member 12 is first welded to the cover 6, whereafter the cover 6 is slid into the shell 1 until the inner surface 18 of the cover 6 abuts against an inner shoulder 19 of the shell 1. In this position of the cover 6, the outer end portion of the semi-toroidal sealing member 12 is welded to the shell 1.

Thereafter, the support elements 7 of the support ring 7 are successively brought into engagement with the internal recess 8 in the wall of the shell 1, in which position their feet 17 rest on the shoulder 15 of the cover 6. Subsequently the locking ring 9 is mounted around the central portion 16 of the cover 6. This locking ring 9 closely fits within the support ring 7 and is connected to the cover 6 by means of the studs 11 and the nuts 11'.

In operation, the cover 6 is subjected to the internal pressure in the channel 4. This load is taken up by the support ring 7, which is maintained in its correct position by the locking ring 9. The semi-toroidal sealing member 12, which is welded to the cover 6 as well as to the shell 1, provides an excellent seal between the cover 6 and the shell 1 and will withstand very high pressures in the channel 4.

When the cover 6 has to be dismounted, the locking ring 9 is removed first, for which purpose the nuts 11' have to be unscrewed. As shown in FIG. 4, the locking ring 9 is not only provided with axial bores for the studs 1 l, but also with a plurality of internally threaded axial holes into which bolts may be screwed, which will abut against the cover 6 so as to loosen the locking ring 9.

The shell 1 is provided with transversely directed cross bores 21, which open into the recess 8. The number of these cross bores 21 corresponds to the number of the support elements 7 of the support ring 7. These support elements 7' are positioned in the recess 8 in such manner that the center of each element is in approximate alignment with an associated cross bore 21. Further, several support elements 7 have side walls, which are parallel with the associated cross bore 21. In the embodiment shown in FIG. 3, the elements 7 on the left-hand side and on the right-hand side are shaped in this manner.

Pins may be inserted in the cross bores 21 of the shell 1 in order to loosen the support elements 7 of the support ring 7 successively from the recess 8. After the semi-toroidal sealing member 12 has been cut through, e.g., by burning or grinding, the cover 6 may be removed from the shell 1. In this manner the channel 4 is easily accessible.

Although the closure according to the invention has been described hereinbefore in detail with reference to the channel of a heat exchanger, it is to be understood that the invention is not restricted to this application,

but may also be used with advantage for sealingly closing pressure vessels other than channels of heat exchangers.

Thus, the invention is not restricted to the illustrated embodiment which may be varied within the scope of the appended claims.

What is claimed is:

l. A device for sealingly closing a metal pressure vessel, comprising a metal cover supported in the pressure vessel, a support means retaining the cover in said vessel, said support means comprising an annular member subdivided into a plurality of support elements, said vessel having a circumferential internal recess partially the latter facing the support means.

2. A device according to claim 1, wherein the pressure vessel is cylindrical, said annular member being a subdivided support ring, said locking means comprising a locking ring which fits within said support ring and which is provided with a plurality of axial bores and a plurality of internally threaded axial holes, said detachable locking means comprising threaded fasteners engageable in threaded holes in said cover throu said axial bores in said lockin ring.

3. device according to claim 1 ifiierem said pressure vessel is provided with transverse bores which open into said internal recess and which are each substantially centrally aligned with a respective support element in said internal recess, a plurality of said support elements having side walls which are parallel with the associated transverse bore.

4. A device according to claim 1 wherein said semitoroidal ring faces said support elements and is internally open to the pressure in said vessel and externally confined by said cover and said support elements bounding said chamber.

5. A device according to claim 1 wherein said cover has an annular shoulder, which adjoins said recessed circumferential portion and which surrounds and defines a protruding central portion for said cover, said locking means fitting around said central portion and resting together with said support means, against said shoulder.

6. A device according to claim 1 wherein said vessel has an internal shoulder against which the cover rests in said recessed relation. 

1. A device for sealingly closing a metal pressure vessel, comprising a metal cover supported in the pressure vessel, a support means retaining the cover in said vessel, said support means comprising an annular member subdivided into a plurality of support elements, said vessel having a circumferential internal recess partially receiving the support elements, a detachable locking means securing the support elements in said recess, said cover being provided with a recessed circumferential portion which, together with the pressure vessel and the support means, defines an annular chamber, and a circumferential metal sealing member in said chamber, said sealing member consisting of a hollow semi-toroidal ring, which opens towards the pressure vessel, said ring having one circumferential edge welded to the pressure vessel and a second circumferential edge welded to said cover on the surface of the latter facing the support means.
 2. A device according to claim 1, wherein the pressure vessel is cylindrical, said annular member being a subdivided support ring, said locking means comprising a locking ring which fits within said support ring and which is provided with a plurality of axial bores and a plurality of internally threaded axial holes, said detachable locking means comprising threaded fasteners engageable in threaded holes in said cover through said axial bores in said locking ring.
 3. A device according to claim 1 wherein said pressure vessel is provided with transverse bores which open into said internal recess and which are each substantially centrally aligned with a respective support element in said internal recess, a plurality of said support elements having side walls which are parallel with the associated transverse bore.
 4. A device according to claim 1 wherein said semi-toroidal ring faces said support elements and is internally open to the pressure in said vessel and externally confined by said cover and said support elements bounding said chamber.
 5. A device according to claim 1 wherein said cover has an annular shoulder, which adjoins said recessed circumferential portion and which surrounds and defines a protruding central portion for said cover, said locking means fitting around said central portion and resting together with said support means, against said shoulder.
 6. A device according to claim 1 wherein said vessel has an internal shoulder aGainst which the cover rests in said recessed relation. 